<Rant On>
Last year I bought a new vacuum for my place. I've always believed that the bitterness of poor quality lasts long after the sweetness of low price has been forgotten, so I tend to buy things that will last. This time, I bought a Dyson DC07 all-floor model.

I've loved it. It's easy to use, easy to clean out, and like the advertising says, it doesn't lose suction.
But I have very sheddy carpets, and today I needed to clean out the roller brush, so I thought I'd just pull it out.
Long story short: After not being able to figure out how, spending an hour on the web looking for the instructions, and finally calling my local vacuum repair shop, the answer is:
You can't.If the belt breaks, you have to take it in to have it replaced. And they have to replace the entire clutch assembly in the process. And it will cost you about $125.00 with parts, and labor.
Holy flapping scrith! The whole flipping vacuum cost me about $400.00... so I need to pay ¼ the value of the machine to replace a $2.00 part?
Analogy: "Sure, Mr. or Mrs. American Car Owner. We'd be happy to replace your oil filter for you. But to do so, we have to pull the engine and replace the head assembly, and it will cost you $8,000.00".
Hello‽‽‽ Dyson engineers! What in the name of Zeus and the Music of the Spheres were you smoking when you designed that‽‽‽
I am moved nigh unto blasphemy - and you can bet I'm going to have words for the company when they re-open on Monday. If I had known this up front, there is
no way I would have bought this vacuum, in spite of all its other good features.
Well, I'm not going to take it sitting down. When the time comes that I actually have to replace the belt, I'm going to learn how to do this myself, by hook or by crook.
Do yourselves a favor, folks.
Don't buy one of these vacuums until they've re-engineered that glaring design flaw.
Mogg! That is so flipping
stupid! 
<Rant Off>